Stack Management

Functions for creating, initializing, maintaining and handling a task's stack. More...

Macros
#define	portINITIAL_XPSR   ( (uint32_t)0x01000000u )
	initial XPSR value for a task.
#define	MY_STACK_SIZE   ((StackSize)0x80u)
	Default value for a task's stack size.
#define	IDLE_TSK_STACK_SIZE   ((StackSize)0x60u)
	Stack size for the IDLE Task.
#define	STACK_BLOCK_SIZE   ((uint8_t)0x4u)
	Size of one stack element in byte.

Typedefs
typedef uint16_t	StackSize
	Used to describe the size of a stack.
typedef uint32_t	StackTypeT
	Base type of a stack element.
typedef StackTypeT *	StackPtrT
	Pointer to a StackTypeT. More...

Functions
RetCode	stk_StackCreate (register PTskTCB tsk, register StackSize desiredStackSize)
	Creates a stack for a task with the size of desiredStackSize. More...
RetCode	stk_StackInit (register PTskTCB tsk, void *fktParam)
	Initializes the initial stack frame according to the given input parameters. More...
RetCode	stk_StackDestroy (register PTskTCB tsk)
	Destroys the stack of the task indicated by the tsk input parameter. More...
RetCode	stk_TSTStck (PTskTCB const tsk)
	fill the task's stack with a distinctive pattern. More...
RetCode	stk_StackClear (PTskTCB const tsk)
	Clears the provided task's stack. More...

Detailed Description

Functions for creating, initializing, maintaining and handling a task's stack.

Typedef Documentation

typedef StackTypeT* StackPtrT

Pointer to a StackTypeT.

Also used to point to the current, the top and the bottom StackTypeT.

Function Documentation

RetCode stk_StackClear

(

PTskTCB const

tsk

)

Clears the provided task's stack.

//ToDO IMPLEMENT FUNCTION

Parameters

[in]

tsk

Pointer to the task's TskTCB

Returns

Return the success of the operation

Sets all stack elements to zero regardless of the current stack pointer's position.

RetCode stk_StackCreate	(	register PTskTCB	tsk,
		register StackSize	desiredStackSize
	)

Creates a stack for a task with the size of desiredStackSize.

Parameters

[in]	tsk	Pointer to the task's TskTCB
[in]	desiredStackSize	Size of the stack to be created

Returns

Return the success of the operation

Allocates memory and creates the stack for the task and sets all pointers for stack management in the TskTCB.

RetCode stk_StackDestroy

(

register PTskTCB

tsk

)

Destroys the stack of the task indicated by the tsk input parameter.

Parameters

[in]

tsk

Pointer to the task's TskTCB whose stack shall be destroyed

Returns

Return the success of the operation

Destroys the given stack and frees all resources. //ToDO Also checks for stack overflow and underflow.

RetCode stk_StackInit	(	register PTskTCB	tsk,
		void *	fktParam
	)

Initializes the initial stack frame according to the given input parameters.

Parameters

[in]	tsk	Pointer to the task's TskTCB, which contains all needed parameters
[in]	fktParam	Pointer to the input parameter that shall be passed to the task ( NULL means no input parameter )

Returns

Return the success of the operation

Builds the initial stack frame needed for switching the context to the task's beginning according to the provided input parameters. Adjusts the task's stack pointer accordingly.

RetCode stk_TSTStck

(

PTskTCB const

tsk

)

fill the task's stack with a distinctive pattern.

Parameters

tsk	Pointer to the task's TskTCB whose stack shall be marked.

Returns

Returns the success of the operation.